Synthesis of metallic glasses and metallic glass based composites in the Cu-Mo-Hf system by ion beam mixing

Abstract

Single-phase and dual-phase metallic glasses as well as metallic glass based composites were synthesized in the Cu-Mo-Hf ternary metal system by 200 keV xenon ion beam mixing of far-from-equilibrium. It was found that Mo-Hf-based and Cu-Mo-based single-phase metallic glasses could be obtained at compositions around Cu17Mo20Hf63 and Cu34Mo57Hf9, respectively. Interestingly, at the nearly equal-atomic stoichiometry of Cu38Mo31Hf31, a dual-phase Cu-Mo-Hf metallic glass, consisting both of the Mo-Hf-based and Cu-Mo-based phases, was first obtained at relatively low irradiation doses ranging from (1–5)×1015 Xe+/cm2, and a single-phase metallic glass was eventually obtained at a dose of 7×1015 Xe+/cm2. In addition, two glass-based composites were obtained at the compositions of Cu14Mo62Hf24 and Cu77Mo14Hf9, and they consisted of the Mo-Hf based and Cu-Mo based metallic glasses, dissolved with some uniformly distributed BCC Mo-based and FCC Cu-based crystalline solid solutions, respectively. The formation mechanism of the above described non-equilibrium alloy phases was also discussed in terms of the atomic collision theory.